1. Field of the Invention
The present invention relates to methods and apparatuses of checking the mount quality of a circuit board. More specifically, the present invention relates to a mount quality checking method for designing a circuit board that satisfies the target quality by predicting the quality of the circuit board having electronic components mounted thereon by a mounting device, a method of displaying a virtual 3D image showing a mount state for the mount quality check, and an apparatus using either or both of the methods.
2. Description of the Background Art
Conventionally, for designing a circuit board, designers refer to a design manual or use a design rule check (DRC) in a CAD system for trying to comply with predetermined design standards in order to determine component arrangement positions, pattern shapes, land shapes, and others. Also, the designers manufacture a prototype of a designed circuit board to see if any problem may occur at the time of manufacturing, or the designers have a 2-D image (virtual prototype) showing the mount state of the circuit board displayed on a screen of a computer device to see if any problem may occur or not. Then, the designers give some feedback about the found problem to the design.
By repeating such a designing-to-prototyping (virtual prototyping) process several times like a loop, the mount quality of the circuit board can be ensured when mass-produced.
To further improve the mount quality, some methods are suggested in Japanese Patent Laid-Open Publication Nos. 9-330342 (1997-330342) and 11-175577 (1999-175577) for predicting and checking the mount quality of the circuit board.
In these methods, the mount quality is predicted only from device data such as the shapes of the components and the shapes of the circuit board, that is, without consideration of a variety of mounting devices and mounting processes. In fact, depending on the mounting device to be used, a pitch between mount components can be determined to be a narrow one (if a small nozzle is used or high-precision positioning is possible, for example) or a standard one.
In Japanese Patent Laid-Open Publication No. 11-330784 (1999-330784), a method of checking the mount quality in consideration of a circuit board manufacturing process is disclosed, which is shown in FIG. 37.
In this method, reference rules for manufacturing are registered in advance in a factory (manufacturing) section. A design section checks designed parts according to design rules which are formulated based on the reference rules.
In the above conventional methods, however, based on the operation requirements of the mounting devices and the requirements of the mount process, the operators have to derive a check value for each check part on the circuit board and refer to the derived check values as manufacturing reference rules. Therefore, if the requirements of the mounting devices, materials, and others are changed, it is not easy to predict how such change will affect the reference rules.
To ensure the mount quality, productivity may have to be decreased in some cases. For example, depending on the mounting device, the operational speed may have to be reduced to ensure accuracy. Also, processing may have to be carried out mainly by a specific facility at the cost of a load balance among the facilities.
On the design side, a plurality of processes may be taken for changing the design to ensure the mount quality. Among these methods, the designer is supposed to appropriately select a highest-productive, lowest-cost method, but he/she may have difficulty doing so at the time of changing the design in consideration of both productivity and cost.
In the conventional method of virtually making a prototype for displaying the mount state of the circuit board on the screen of a computer device, the components are displayed only by two-dimensional plane graphics. Therefore, when two components which differ in their respective upper shapes ((a) of FIG. 38) are two-dimensionally displayed, they look the same ((b) of FIG. 38). Also, when two components which differ in their respective heights ((c) of FIG. 38) are two-dimensionally displayed, they look the same ((d) of FIG. 38). Therefore, a detailed check of the mount requirements as to the shape and height of the components cannot be performed, and a sufficient study therefore cannot be made.
Therefore, an object of the present invention is to provide a method of checking the mount quality of a circuit board, a method of displaying the mount state of circuit board in a virtual three-dimensional display, and an apparatus using either or both of the above methods. With these methods and apparatus, if the mounting process to be used, the operation requirement of the mounting device, and others are changed, such a change can be easily reflected on the design check. Therefore, consideration of the mount quality during the mounting procedure reduces the number of quality checks onto the actual prototype, and the circuit board that satisfies the target quality can be designed in the early stage of designing.
The present invention has the following features to attain the object above.
A first aspect of the present invention is directed to a method of checking a mount quality of a circuit board having components mounted thereon by a mounting device, and the method includes the steps of:
receiving board information related to the circuit board to be used in a designed circuit, component information related to the components to be used, and position information related to a mounting position of the component;
receiving a mount requirement specifying a mounting process and a mounting device to be used in manufacturing the circuit board; and
checking, based on a requirement for the mounting process and a requirement for operation of the mounting device, to see whether the circuit board manufactured from the board information, the component information, and the position information under the mount requirement can satisfy a predetermined target mount quality.
As such, in the method according to the first aspect, the requirements are registered in advance for respective mounting processes and mounting devices. When the mounting process to be used and/or the operation requirements for the mounting device is/are changed, the change is easily reflected on a design check. Therefore, consideration of the mount quality during the mounting procedure reduces the number of quality checks onto the actual prototype, and the circuit board that satisfies the target quality can be designed in the early stage of designing.
Preferably, the check in the method according to the first aspect is made based on the requirement for the mounting process and the requirement for operation of the mounting device in order to see whether the circuit board manufactured from the board information, the component information, and the position information under the mount requirement can satisfy a predetermined target productivity.
As such, by checking the mount quality of the circuit board and the productivity (cost), it is possible to design a lower-cost circuit having more productivity and satisfying the requirements for the target mount quality.
Here, the component information includes at least a number, a shape, a packaging, and a size of each of the components. The board information includes at least a material, a shape, a thickness of the board, a land shape, a printed mask shape, and a position correction mark shape of each of the components. The requirement for the mounting process includes at least soldering processes, a soldering material to be used, and a board process/inspection after the components are mounted. The requirement for operation of the mounting device includes at least a mountable component type, a mount accuracy for each of the components, a mount cycle time, and a mountable range. The mount quality is checked as to at least the mounting position of the component, a state of soldering, a board process/inspection after the components are mounted, and a state of holding an outer shape of the board.
By checking the mount quality with the above information and requirements, it is possible to quickly and correctly design a circuit board satisfying the target quality.
Also, the component information and the requirement for operation of the mounting device is preferably retrieved from a CAM system that generates operation data (NC data) of the mounting device.
As such, the component information and the requirement for operation of the mounting device are retrieved from the CAM system side, thereby avoiding data redundancy and reducing the workload.
Furthermore, the requirement for the mount process and the requirement for operation of the mounting device is preferably changed based on the quality of the performance of the circuit board which is actually manufactured.
As such, the performance of the circuit board which is actually manufactured is fed back to the requirements, thereby allowing for the circuit board to be quickly and correctly designed with less of a defective condition at the time of the next circuit board is designed.
Still further, when the mount quality is rechecked after the circuit board is changed, only a range corresponding to a portion which was changed or a portion at which an error occurred is preferably checked.
As such, only a range corresponding to a portion which was changed or a portion at which an error occurred is rechecked. Such a limited-area recheck requires less time than an entire-board recheck.
A second aspect of the present invention is directed to a method of virtually displaying a state of the electronic components mounted on a circuit board by one or more mounting devices based on the data used by the mounting devices. The method includes the steps of:
receiving, as the data used by the mounting devices, circuit board data including information about a mounting position and a shape of each component mounted on the circuit board, and information about a shape of the circuit board;
receiving, for each of the mounting devices, facility operation data including information about operation requirements of the mounting device, such as a type and a falling position of a suction nozzle to be used, an allowable distance between the components, and an operable area;
storing the circuit board data and the facility operation data;
selecting a circuit board from the stored circuit board data to be displayed in 3D;
generating 3D graphics data for displaying outer shapes of the circuit board and the components at respective mounting positions by retrieving data required for the circuit board data of the selected circuit board from the stored facility operation data, and calculating data representing a state of the circuit board having the components mounted thereon; and
displaying an image based on the generated 3D graphics data.
In the method according to the second aspect, the mount state of the circuit board is displayed in 3D with the components mounted thereon based on the received mount data (the circuit board data and facility operation data), and the operation requirements for the mounting device to be used are also displayed in 3D. Thus, the mount data can be virtually checked without using any prototype of the actual board, and it is also more reliably evaluated. By reducing the workload of the designer by obviating the need to make a prototype, the electronic components can be mounted within a shorter period of time and at a lower cost. Moreover, the method according to the second aspect of the present invention is also applicable to a case where the components are mounted by a plurality of mounting devices.
Preferably, the 3D graphics data is generated for displaying positions of the components after they are mounted, a component assignment to each mounting device, an order of mounting the components, and a state of any component being sucked by a suction nozzle in 3D. Also, a mounting operation is displayed by successively displaying moving images according to the order of mounting the components.
By displaying the mount state of the circuit board by using the above information and display process, the mount data can be checked more quickly and reliably.
Also, the stored circuit board data or the stored facility operation data is preferably changed with regard to component information, mounting position information, a type or falling position information of a suction nozzle, and the changed data is then stored.
At this time, more preferably, a storage time of the changed data is stored as history. Also, when an image is displayed based on 3D graphics data newly generated from the changed data, the 3D graphics data generated before the changed data is searched for from the stored history, and the image is displayed based on the 3D graphics data after the changed data and the 3D graphics data before the changed data to show a difference in the mount state after the change. Furthermore, the 3D graphics data after change is stored in relation to the storage time as the history.
As such, by displaying and checking the changed mount data through a 3D image, the mount data can be changed and checked more quickly and correctly.
Furthermore, preferably, when the component cannot be mounted at the mounting position specified in the circuit board data, an error-state 3D graphics data is generated for representing a defective part or the cause thereof, and the image is displayed based on the 3D graphics data and the error-state 3D graphics data.
As such, the defective part in the mount data can be checked and displayed in advance. Therefore, it is possible to easily find any part which needs to be corrected before actually starting the mounting of the components.
Still further, operation requirements for one or more inspecting devices for inspecting the mount state of the electronic components are preferably received. By using the information about the mounting positions included in the circuit board data as inspection position information, 3D graphics data is generated for displaying a component assignment for each inspecting device, an order of inspecting the components, and a possible range which is interfered by a facility operation in 3D.
As such, by applying the method according to the second aspect of the present invention to the inspecting device, the inspection state of the circuit board having components mounted thereon can be displayed in 3D together with the operation requirements for the inspecting device to be used. Thus, it is possible to virtually check a defective condition in the inspection state by a board inspection process without using any prototype of the actual board, and the check can be made more reliably.
A third aspect of the present invention is directed to an apparatus for checking the mount quality of a circuit board having components mounted thereon by a mounting device. The apparatus includes:
a data input unit for receiving board data corresponding to a circuit board used for a designed circuit, component data corresponding to components to be used, and position information corresponding to mounting positions of the respective components;
a circuit board information storage having information corresponding to available boards previously stored therein, and for outputting board information corresponding to the board data;
a component information storage having information corresponding to available components stored therein, and for outputting component information corresponding to the component data;
a mounting process requirement storage having requirements for respective available mounting process stored therein;
a mounting device requirement storage having requirements for operations of the respective available mounting devices;
an applied mount requirement input unit for inputting mount requirements specifying a mounting process and a mounting device to be used in manufacturing the circuit board; and
a design analyzer for checking, based on the requirements for the mounting process and the mounting device, whether target mount quality and productivity can be satisfied by the circuit board manufactured based on the board information, the component information, and the position information under the mount requirements.
According to the apparatus of the third aspect, the requirements are registered in advance for the respective mounting processes and mounting devices. Therefore, when the mounting process to be used and/or the operation requirements for the mounting device is/are changed, the change is easily reflected onto the design check. Therefore, consideration of the mount quality during the mounting procedure reduces the number of quality checks onto the actual prototype, and the circuit board that satisfies the target quality can be designed in the early stage of designing.
Preferably, each of the requirements for the mounting process and the mounting device is changed based on the performance of the mount quality when the circuit board is actually manufactured.
As such, the performance of the circuit board actually manufactured is fed back to the requirements, thereby quickly and correctly allowing the designer to design a circuit board with less of a defective condition at the time the next circuit is designed.
Also, when the mount quality is rechecked after the circuit board is changed, the design analyzer preferably checks only a predetermined area corresponding to a changed part or a part in which an error occurred.
As such, only a range corresponding to a portion changed or a portion at which an error occurred is rechecked. Such a limited-area recheck requires less time than an entire-board recheck.
Here, according to the apparatus of the third aspect of the present invention, the design analyzer includes:
a circuit board data storage for receiving and storing circuit board data used in the mounting device, where the circuit board data includes information corresponding to mounting positions and shapes of the components mounted on the circuit board and a shape of the circuit board;
a facility operation data storage for receiving and storing facility operation data related to the mounting device, where the facility operation data includes information corresponding to a type and falling position of a suction nozzle to be used, an allowable distance between the components, and an allowable operation range;
a data selector for selecting a circuit board from the stored circuit board data to be displayed in 3D;
a data generator for generating 3D graphics data for displaying outer shapes of the circuit board and the components at respective mounting positions by retrieving, from the stored facility operation data, data required for the circuit board data of the selected circuit board, and for calculating data representing a state of the circuit board having the components mounted thereon; and
a data display unit for displaying an image based on the generated 3D graphics data.
With such a structure, the mount state of the circuit board can be displayed in 3D with the components mounted thereon based on the received mount data (circuit board data and facility operation data), and the operation requirements for the mounting device to be used can also displayed in 3D. Thus, the mount data can be virtually checked without using any prototype of the actual board, and thus, the mount data can also be more reliably evaluated. By reducing the workload of making a prototype, the electronic components can be mounted within a shorter period of time and at a lower cost. Moreover, the method according to the second aspect of the present invention is also applicable to a case where the components are mounted by a plurality of mounting devices.
Furthermore, the data generator preferably generates the 3D graphics data for displaying, in 3D, the positions of the components after they are mounted, a component assignment for each mounting device, an order of mounting the components, and a state of any component being sucked by a suction nozzle. Also, the display unit displays a mounting operation by successively displaying moving images according to the order of mounting the components.
By displaying the mount state of the circuit board by using the above information and display process, the mount data can be checked more quickly and reliably.
Still further, the design analyzer further preferably includes a data editor for changing the stored circuit board data or the stored facility operation data with regard to component information, mounting position information, a type or falling position information of a suction nozzle, and for then storing the changed data.
Still further, the design analyzer further preferably includes a data history manager for storing a storage time of the changed data as history and storing the 3D graphics data generated based on the changed data in relation to the history. Also, when an image is displayed based on 3D graphics data newly generated from the changed data, the data display unit searches the 3D graphics data before the changed data from the stored history, and displays the image based on the 3D graphics data after the change and the 3D graphics data before the change to show a difference in the mount state after the change.
As such, by displaying and checking the changed mount data through a 3D image, the mount data can be changed and checked more quickly and correctly.
Still further, when the component cannot be mounted at the mounting position specified in the circuit board data, the data generator preferably generates an error-state 3D graphics data for representing a defective part or the cause thereof Also, the data display unit displays the image based on the 3D graphics data and the error-state 3D graphics data.
As such, the defective part in the mount data can be checked and displayed in advance. Therefore, it is possible to easily find any part which needs to be corrected before actually starting the mounting of the components.
Still further, the facility operation data storage further preferably receives operation requirements for one or more inspecting devices for inspecting the mount state of the electronic components, and the data generator further generates 3D graphics data for displaying a component assignment for each inspecting device, an order of inspecting the components, and a possible range which is interfered by a facility operation in 3D by using the information about the mounting positions included in the circuit board data as inspection position information.
As such, by applying the method of the present invention to the inspecting device, the inspection state of the circuit board having components mounted thereon can be displayed in 3D together with the operation requirements for the inspecting device to be used. Thus, it is possible to virtually check a defective condition in the inspection state without using any prototype of the actual board, and the check can be made more reliably.
Typically, the mount quality check method and mount state display method according to the above first and second aspects of the present invention are realized by a computer device executing a predetermined program in which the procedure of each method is programmed. The predetermined program may be previously stored in a storage device (ROM, RAM, hard disk, etc.) incorporated in the computer device, or may be loaded into the computer device through a program-writable recording medium (CD-ROM, floppy disk, etc.)